Online shopping extends the basic concepts of mail order shopping to the Internet. A user selects an item from a catalogue, places an order, and receives delivery of the ordered item via the mail. Waiting for delivery, paying for postage, and/or being physically present to receive some orders, however, may be too much of a burden for the purchase of a number of goods. In addition to or in lieu of delivery, some businesses allow users to order items for pickup at a local store. For example, a website may enable a user to search for and select a store location, place an order for an item, and pickup the order by presenting a printed copy of a receipt, a credit card, etc. The user experience of shopping for items on store websites or across multiple store mobile device applications often leads to a poor customer experience. Additionally, even if a central shopping platform is provided for multiple retailers, tracking and maintaining product data across the different retailers and retail locations is challenging. It is especially challenging when dealing with data that may change rapidly, such as the inventory of items.